fix(deps): update dependency mysql2 to v3 [security]

Author: renovate[bot]

package-lock.json

@@ -56,7 +56,7 @@
     "mime-types": "2.1.27",
     "moment": "2.26.0",
     "multer": "1.4.2",
-    "mysql2": "2.1.0",
+    "mysql2": "3.9.8",
     "nest-emitter": "1.1.0",
     "nest-raven": "5.0.0",
     "reflect-metadata": "0.1.13",